1. Field of the Invention
The present invention concerns a concrete machine, more particularly a concrete machine which is provided with a height adjustment and which preferably can be equipped with different tools for producing ditches, sidewalks, concrete paths or the like.
2. Discussion of the Related Art
Such a concrete machine which is mainly composed of a caterpillar drive provided with several supporting arms supporting a chassis is already known.
In this known concrete machine, the caterpillar drive is provided with means, for example a hydraulic piston, which makes it possible to move the above-mentioned supporting arms vertically or almost vertically.
The chassis of the known concrete machine is further provided with means which make it possible to fix an aforesaid tool on a side of the chassis or under the chassis.
A disadvantage of this known concrete machine is that, in order to adjust the tool in height, the entire chassis always has to be adjusted together with the above-mentioned arms.
This is disadvantageous in that the center of gravity of the concrete machine will be situated relatively high, when a tool is used which is relatively high itself or when there is a large difference in level between the working area and the driving area of the caterpillar drives, which results in a reduced stability of the concrete machine, so that, when constructing a road or the like, the finish of the road surface will be poor.
Another disadvantage is that the adjustment in height of the chassis is limited and in that the arms which support the chassis cannot be lowered under the level of the caterpillar drives, as a result of which , in order to work a surface situated under the level of the caterpillar drive, for example when working in ditches, the tool concerned must have a relatively large height, as it must bridge the distance between the chassis and the working area.
This is disadvantageous in that different tools must be provided having the same function but with a different height, so that not only a lot of tools will have to be acquired, but as a result of which, in many cases, the number of tools also forms a major disadvantage for the mobility of the concrete machine between for example different construction sites.